[Goose]

Asymptomatic transmission is probably a big deal: https://www.cnn.com/2020/03/14/health/co...index.html



It's probably a big factor in why the R0 is so high.



Goose, the answer to your question is in that article:

Unfortunately, no, the answer to my question is not in the article, although it does have some attempts in that direction. The article shows that for some individuals "the test" can detect the virus before the individuals show symptoms. In other words, for some unknown n a test (the test was not designated as which test. One could assume the "German" test but it is not so stated) can sometimes detect the virus n days before symptoms where n is not known.

If somebody followed up on the four Israeli and one German patient and told us when (or even if) they showed symptoms, we would have maybe 5 data points for the "German" test, if that is what was used. Since the letter for the German national came out on 18 Feb, it is well past time for that patient to show symptoms, but the number was not available. What really bothers me is that by now one would hope there would be plenty of examples of this situation. Even with the current limited testing, you can test people who been exposed but do not show symptoms. How often has the test come up positive? If the 5 cases reported on in the article are all there are, "the test" is pretty useless as a predictor. Even in those cases, we don't get told how "early" the prediction was. Four of those cases may be too early to know, if n is > 2 days, but there should be other data points, lots of them.Perhaps the current tests are not generally useful in detecting disease in asymptomatic patients. That is why I asked the question in the first place. The Chinese protocol has the same attribute. It may be because the assumption is (was) you had to have symptoms to spread the disease that testing asymptomatic people was not generally done. However, it was done on lots of travelers fleeing areas where they had been exposed. Why no results in the public domain?
It is also true that there are many tests in use. Stanford is now deploying another, different test in California. Probably all these tests "work", but probably they don't work exactly the same. The complicates the question of "Can the test X be used for early detection of asymptomatic individuals?". It is still early days for this disease and the tests, but I am not encouraged by what I have seen in the press.

[Goose]

Asymptomatic transmission is probably a big deal: https://www.cnn.com/2020/03/14/health/co...index.html



It's probably a big factor in why the R0 is so high.



Goose, the answer to your question is in that article:

Unfortunately, no, the answer to my question is not in the article, although it does have some attempts in that direction. The article shows that for some individuals "the test" can detect the virus before the individuals show symptoms. In other words, for some unknown n a test (the test was not designated as which test. One could assume the "German" test but it is not so stated) can sometimes detect the virus n days before symptoms where n is not known.

If somebody followed up on the four Israeli and one German patient and told us when (or even if) they showed symptoms, we would have maybe 5 data points for the "German" test, if that is what was used. Since the letter for the German national came out on 18 Feb, it is well past time for that patient to show symptoms, but the number was not available. What really bothers me is that by now one would hope there would be plenty of examples of this situation. Even with the current limited testing, you can test people who been exposed but do not show symptoms. How often has the test come up positive? If the 5 cases reported on in the article are all there are, "the test" is pretty useless as a predictor. Even in those cases, we don't get told how "early" the prediction was. Four of those cases may be too early to know, if n is > 2 days, but there should be other data points, lots of them.Perhaps the current tests are not generally useful in detecting disease in asymptomatic patients. That is why I asked the question in the first place. The Chinese protocol has the same attribute. It may be because the assumption is (was) you had to have symptoms to spread the disease that testing asymptomatic people was not generally done. However, it was done on lots of travelers fleeing areas where they had been exposed. Why no results in the public domain?
It is also true that there are many tests in use. Stanford is now deploying another, different test in California. Probably all these tests "work", but probably they don't work exactly the same. The complicates the question of "Can the test X be used for early detection of asymptomatic individuals?". It is still early days for this disease and the tests, but I am not encouraged by what I have seen in the press.